Eclipse needs to implement the Scroll Lock button. I know it sits there and is often ignored. But when browsing and inspecting code it's easy to accidently press the wrong button. Especially on a laptop where if num-lock is in the wrong state you mean to press 'Pg-Up' but press 'U' instead and demolish a small part of the code. And in CDT the ridiculous ctrl+shift+b to set a breakpoint, which often comes out as ctrl+v paste or 'B' or something else. Or using the mouse and accidentally dragging text.

Scroll lock key is for "just looking" mode. So turning on scroll lock should stop any modifications to the document until it's turned off again.